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In the previous paper'~, we discussed the process and mechanism of the progressionof the local scour in the alluvial curved channels on the basis of the experimental studies, and developed the theoretical analysis for the variation of lateral bed profiles at the initialstage of scour.This paper proposes an analytical approach for the progressive stage of scour, whichdescribes the longitudinal variation of bed profile with time along the outside wall ofcurved reach. The fundamental equations derived in this analysis include two unknownfactors. The one is characteristics of flow pattern near the scour hole, and the other isthe variation of stream width near the outside wall or longitudinal profiles of lateralscour front with time. Concerning to these problems, we discuss the results of themeasurements of flow direction and velocity near the bed and the observation of Dunes(Bars) in the curved reach.

The present paper deals with the seasonal variation of the shape of the Fujinoki delta usingshape parameters defined in the preceding paper. The effect of wind waves on the shape varia-tion of the delta is also discussed with th.e aid of the equivalent wave energy estimated from squaremean wave heights.Characteristics of annual sediment discharge of the Fujinoki river is deduced from correla-tion between the drainage area and the equivalent deltaic area of twenty nine rivers, assuming thepower law between water discharge and sediment discharge of a river.

After the World War II, in addition to the poor social and economical conditions, Japanwas suffered from the great flood disaster resulting from typhoons every year. Under thesecircumstances, the authors emphasized that the disaster prevention program including econo-mical considerations must be established and that it is necessary to introduce the technique ofhydrological statistics in determining this program. Moreover, in planning the reasonableflood protection project, it was our urgent problem to disclose the physical and hydrologicalcharacteristics of runoff phenomena during floods.To achieve those ends, the hydrological observation program in the model basin of theYura River has been continued since 1951 by the authors. As the result of this program, agreat deal of hydrological data have been obtained and, by using those data, many successfulanalyses with respect to the flood runoff have been performed. These results of investiga-tions have been presented to various publications.In this paper, the outline of this hydrological observation program is historically explained, for past ten years, and the results obtained by the authors' studies with respect to runoffphenomena, especially during floods, are summarized. And this paper is written in memoryof the tenth anniversary of the Disaster Prevention Research Institute, Kyoto University.

Lateral buckling phenomenon is one of the most important factors to determine the maxsmumload carrying capacity of H-shaped beams. This paper presents the results of numerical analysisof the elastic lateral buckling load of H-shaped beams under various types of bending moments;unequal end moments, bending moments due to uniformly distributed load and combined mo-ments of these two. Generally, partial differential equations in equilibrium condition are impos-sible to solve analytically. In this paper, basic equations are replaced by finite difference equations.Lateral buckling load is obtained as the load at which the stiffness matrix of the beam becomessingular. As the results of analysis, it is observed that the acting location in vertical direction ofuniform load significantly affects upon the lateral buckling load. Non-dimensioned bucklingload is quasi-linear to the span length of beams. On the other hand, it is also confirmed thatthe lateral buckling load of the beams subjected to not only end moments but uniformly dis-tributed load, is given as a very complex function of dimension of cross-section, end moment ratio(α), magnitude of uniformly distributed load (β) and span length (L). Appropriate formulationfor design is urgently needed considering the combination of the above-mentioned factors.

This paper deals with the surface profiles of a mud flow for gradually varied flowin an open channel.The obseved surface pzo~iJes of the mud flow is steeper in spite of consideration forfriction increase than a profile which is culcalated by ordinarily used equation of graduallyvaried flow.In this paper anthors introduced a diviator normal stress due to a visco-elasticitycharacter of fluid into the equation of g~aduaIly varied flow ~nd compared a gradientdue to that stress with the experimental reslts.

The previous paper proposed the formulas of various wave characteristics of thenew waves named "hyperbolic waves" derived from the cnoidal wave theory under thecondition that K~3, in which K is the complete elliptic integral of the first kind.This paper gives firstly the equations of total energy and energy transmission ofhyperbolic waves of the second approximation, and proposes the relation between K andthe wave period, wave height and water depth to be applied in the region where theratio of wave height to water depth is greater than 0. 55. This gives more exact valuesthan that proposed in that region in the previous paper. Secondly, as an application ofthe hyperbolic wave theory, the present paper deals with wave shoaling, that is changesin the wave height, wave crest height above the still water level, and wave length orwave velocity, when the waves proceed into shallow water from deep water. Thetheoretical curves are then compared with the results of existing experiments.

Few methods for estimating population parameters of two-variate gamma distribution werealready proposed by she authors in the previous papers, but the j~idgement for their merits anddemerits was suspended because of difficulty for its theoretical discussion. In this paper, the tech-nique of the Monte Carlo simulation is applied to generate many data regarded as samples froma population of the two-variate exponential distribution which is a special type of two-variategamma distributions, and the effectiveness of the methods for estimating population parametersof the distribution is discussed from the viewpoints of unbiasedness and efficiency. The resultssn outline are as follows:1) For the case that a sample from a total population is available; the estimates based on themaximum likelihood method give the most desirable results, hut the ones on the moments methodare not except the case using the correlation coefficient.2) For the ease that only a sample from a sub-population in the one-dimensional sense is availa-ble, in which the domain of independent ~ariable is defined as upper tail over a given value; theestimates based on the maximum likelihood method give the good results, but the ones on the mo-ments method are not.3) For the case that only a censord sample in the two-dimentional sense is available, in whichthe domains of both variables are defined as upper tails over given values; no good means arefound for estimating population parameters.

The fifth paper gave firstly the equations of total energy and energy transmission ofhyperbolic waves of the second approximation and secondly theoretical curves on variationsof wave height, wave crest height and wave velocity due to wave shoaling.This paper presents the results of experiments on wave shoaling and comparisons withthe theoretical curves based on hyperbolic wave and Stokes wave theories, which resultin good agreement for wave height variation. In addition, an importance of comprehensivestudies for not only wave height variation but also wave profile deformation in processof wave shoaling is pointed out.

The present paper deals with the application of the geophysical exploration methods on thesubsurface ground structure. It is necessary to simplify the survey for adapt to the condition on theslope ground of mountainous region. The geophysical exploration is the effectual measurementsystem owing to the survey is carry out together with she three methods be based on the seismicand electric ways and penetration test.The writer carried out the survey about the respective charactristics of the three methods on theexperimental fields in Kyoto and Gifts prefecture. In the present paper, the writer is shown in thecases of two popular examples of the survey.

The previous papers dealt with discussions of applicability of the enoidal wave theory fromvarious points of view, and concluded that this theory should be used rather than Stokes wave theorywhen the wave period beomes long. However, these papers did not deal with near breaking waveswith large wave height.This paper firstly presents experimental results of the horizontal water particle velocity underthe wave crest and wave profiles of breakings waves, which were measured by taking photographsof the wave profile and floating tracers on the water surface with 16mm high speed cine camerafollowing the breaking wave.Further the paper deals with the horizontal water particle velocity computed from the enoidalwave theory near breaking, then presents the relation between T√g/h and H/h given by the limitingcondition of wave breaking that the water particle velocity at wave crest is equal to the wave celer-ity, and discusses applicability of this theory to near breaking waves.

In the previous papers, after the graphs and method for computing the wave profile, wave velocity and wave length from a given wave period, still water depth and waveheight were presented based on Laitone's cnoidal wave theory7 the measurements of thewave profile, wave velocity and wave length were carried out, and the comparisons ofthese experimental results with the computed values by the cnoidal wave, Stokes waveand small amplitude wave theo'ries were made.This paper proposes the formulas of various wave characteristics of new waves namedas "hyperbolic waves", which are derived from the cnoidal wave theory under the con-dition that k=1 and E=1 but K芯a, in which k is the modulus of the Jacobian ellipticfunction, and K and E the complete elliptic integrals of the first and second kinds re-spectively.

The Twelfth International Conference on Coastal Engineering was held in Washington, DC, U. S. A. from the 13th to the 18th, September, 1970. At the conference, about 179 papers werepresented for four days. Based on the papers presented and some of recent papers a considerationof the coastal processes is briefly made in addition to an outline of the conference.

Measurement of water particle velocity induced by surface wave motion has been madelittle because of difficulty, while it is important for clarification of wave breaking mecha-nism, wave force on offshore structures, mechanism of sediment suspension and diffusionby waves, and so on.In the 3rd and 6th papers, applicability of the cnoidal wave theory was discussed bycomparison of the experimental results of wave velocity, wave length and wave crestheight with the theoretical values.This paper presents experimental results of horizontal velocity of water particles ina wave tank by two methods, that is, hydrogen bubble tracer and a hot film anemometer.And applicability of the cnoidal wave theory is also discussed herein by comparison of theresults with Stokes wave theory of the 3rd order and the cnoidal wave and hyperbolicwave theories of the 2nd approximation.

A method of numerical analysis for three dimensional unconfined seepage flow was proposed inthe previous paper. Then, few examples for engineering application of the method are shown inthis paper. First, the result calculated for the flow in the three dimensional earth dam was discussedin comparison with the result obtained as two dimensional flow. Moreover, three dimensionalcharacters of ground water flow in a wide alluvial fan are examined using the results calculated bythe method and observed data.

For a storage reservoir constructed on mountainous small river, where flood runoff is very rapid, forecasted storm rainfall depth must be valuable information to do better flood control. But, practically, it is difficult to make the best use of the information, except such a way as preliminaryrelease, because it is impossible to predict flood hydrograph only from rainfall depth.This paper treats with a method to make the best use of storm rainfall depth forecasted justbefore flood. The method is based on the conditional distribution of peak discharge to rainfalldepth and on the assumption of shape of hydrograph for given peak discharge and rainfall depth.Computational examples are also shown.The method discussed here will be applied also to design problem of flood control.

This paper deals with some problems of applying the results of model experiments forpractical purposes, based on the experiment on wave transformation off the Koigahama Coast.The experiment was conducted in the model to horizontal and vertical scales of 1/200. If theeffect of wave damping due to bottom friction is taken into account the basis of laminar boundarylayer theory in addition to the effect of wave refraction and wave shoaling, it is shown that thecomputational results agree relatively well with the experimental results of wave height distribution.Consequently, a method to apply the result of model experiment to practical use is proposed.

This paper treats the wave propagation and its charactevistics due to a shock load buried ina surface ground layer.Analytical and experimental studies are performed. By finite element method, linear andnon-linear vibrational characteristics of surface ground are analyzed and the effect of a length ofstructures, a buried depth of structures and a height of surface layer are investigated. Also, theeffect of trenches to prevent the vibration of a ground are discussed.On the other hand, vibrational experiments are performed in a model ground and also in areal ground. Their results show good agreement to the theoretical results.

In this paper dominant characteristics of the local scour near a cylindrical pier are investigatedon the basis of wide ranged experimental data. And an attempt is performed to explain its char-acteristics by making use of a simple model which is constructed in consideration of only the vortexof the stagnation plane and the continuity of the sediment in the same plane. Secondary, by dis-cussing the existing experimental results and proposals together with their applicability, anothermethod of estimation of the equibilium scour depth is proposed.

This paper deals with the investigation of nonlinear effect of waves on wave pressure and waveforce on a large cylindrical pile. Based on the numerical computation of the second order ap-proximate solution of nonlinear diffraction theory by the authors, it is clarified that nonlinear effectof waves on the maximum total wave force is of less importance except for the case of small valueof the ratio of water depth to wave length. In the next, from the comparison between the theoreticalcurves and the experimental results for wave pressure and total wave force, the validity of the theoryis confirmed. Especially, it is found that the nonlinear effect of waves on the pressure appearsremarkably in front of a pile and that the time variation becomes more asymmetrical toward theside of a pile.

This paper describes the simulation technique of the flood runoff process on a hydraulic model.First, the various rainfalls generated artificially, being similar in shape to the observed hyeto-graphs in the actual river basin under the conditions of the several assumed similitudes, are givenon the model. By comparing the obtained hydrographa in the model with those in the prototype, the similitude available for the model is found out between both systems.Secondly, the elements which cannot be measured directly in the field but is of importance inunderstanding the runoff process, for example, the time-distribution of effective rainfall on theflow through the porous surface layer and the propagation speed of the flow are estimated.Finally, in the light of the similitude determined abo~-e, the characteristics of the hydrographresulting from prompt interfiow on the nonlinearity of runoff components during floods in theprototype is discussed.